Everyone complains about E.T., but no one does anything about it.
30 years after its release, with some time off for the new year, I took a shot at fixing some of the problems like accidentally falling into wells and the punishing difficulty. It turned out really well, and makes for a much better experience.
If you actually step on a well, you'll fall in -- just not when you're clearly on solid ground, as in the image above.
(1) Thanks to Nukey Shay's suggestions, sprites are no longer "blocky".
(2) Thanks to Random Terrain's bug report, the hovering sound works properly.
(3) Fixed Elliott's shirt and made it easier to pickup candy (most of the time).
(4) You can pick-up Candy easily regardless of the circumstances. Items in wells are kept at their original positions. There are no graphical hiccups near the edges of the screen. Elliott's shirt is striped, the FBI agent is no longer bald, and E.T. doesn't get "blocky" near the right-edge of the play area. The difficulty fix can now be enabled and disabled with the color switch. The most important change, of cousre, is that Elliott can now revive you (how did I miss THAT bug?!).
(5) The scoring has been fixed to match the manual. If the difficulty fix is enabled, no points are awarded for remaining energy. Ninja E.T. is back as an easter egg. A few bug fixes and that's all, I think.
A full write-up of the fixed E.T. cartridge is at this page.